Method of transition between wireless voice and data transmissions

ABSTRACT

The invention provides a method of transitioning between voice and data communications with a mobile vehicle. A switch-to-voice command signal is sent from a call center modem pool to the mobile vehicle, and a vehicle switch-to-voice acknowledgement signal is received at the call center. A call from the call center modem pool is switched to a call center advisor in response to the vehicle switch-to-voice acknowledgement signal.

FIELD OF THE INVENTION

This invention relates generally to operating a wireless communicationsystem. More specifically, the invention relates to a method fortransitioning between data and voice segments within a wirelesscommunication session with a mobile vehicle.

BACKGROUND OF THE INVENTION

Many call centers today have network architectures that use distributedmodems at the workstation of each human advisor. Incoming calls mayrequire only one switching event to route the call to an availableadvisor. Once a call has been directed to the workstation of a callcenter advisor, modem multiplexing may separate voice and data segmentswithin a session. The network architecture of these call centers havebeen designed with an emphasis on interactive voice calls with a liveadvisor supported by modems and database access, rather than on callsthat may be directed to an advisor or directed to more automatedresources built on a computer server and database system. A desirablefeature of these architectures is that they can accommodate either dataor voice transmissions over a single voice channel.

Data and voice communications may be sent using a dedicated transportmechanism for data, and a separate voice call over another channel forvoice communications. The two transceivers may be integrated, one ofwhich is used for the voice call and the other for the data call. Thismethod requires a modem line associated with each voice line, resultingin a more extensive use of voice lines and modems than is practical fora large-scale call center, which may receive many thousands of calls ina day.

Call centers that are providing telematics service for mobile vehiclescenter have been offering more services, as well as experiencingtremendous growth in the volume of calls. This growth, which is expectedto continue in the foreseeable future, is in part due to the increasedpercentage of new vehicles being equipped with wireless communicationdevices. Thus, the call centers need to build scalable network systemswith an efficient way to manage the inevitable increase in data andvoice calls, while providing customers with a high quality of serviceand reliability. Ideally, this network system would also benefit fromreduced costs associated with a proper balance between advisor and modemrequirements, and minimized connection time.

Call centers with a large percentage of data calls may benefit from analternative network architecture that uses a centralized modem pool.This alternative approach may be more scalable, efficient and costeffective, though may often require switching between the modem pool andan advisor in order to perform numerous data operations and voicecommunications. The technical challenge in this alternative networkarchitecture becomes the need for rapid and accurate switching betweenvoice and data segments during a single call. The ability to transitionreliably from a voice call to a data call becomes a necessary functionfor the efficient operation of the call center.

It is an object of this invention, therefore, to provide a method fortransitioning between data and voice segments during wirelesscommunications between a mobile vehicle and a call center. Additionally,it offers a method to improve the scalability, increase the efficiencyand reduce the costs of a call center network, as well as overcome theobstacles described above.

SUMMARY OF THE INVENTION

One aspect of the invention provides a method of transitioning betweenvoice and data communications with a mobile vehicle. A switch-to-voicecommand signal may be sent from a call center modem pool to the mobilevehicle. A vehicle switch-to-voice acknowledgement signal may bereceived at the call center. A call from the call center modem pool maybe switched to a call center advisor in response to the vehicleswitch-to-voice acknowledgement signal.

A call center switch-to-voice acknowledgement signal may be sent fromthe call center to the mobile vehicle in response to the vehicleswitch-to-voice acknowledgement signal. A voice-ready mode at the mobilevehicle may be entered in response to the call center switch-to-voiceacknowledgement signal. A voice-ready mode at the mobile vehicle may beentered when a predetermined delay period has elapsed after the vehicleswitch-to-voice acknowledgement signal has been sent.

A switch-to-data command signal may be sent from the call center to themobile vehicle. A vehicle switch-to-data acknowledgement signal may bereceived at the call center from the mobile vehicle. The call may beswitched from the call center advisor to the call center modem pool.

The call at the mobile vehicle may be monitored. A switch-to-datacommand signal may be received at the mobile vehicle from the callcenter. A vehicle switch-to-data acknowledgement signal may be sent fromthe mobile vehicle to the call center. The mobile vehicle may switch toa data-ready mode.

Another aspect of the present invention provides a computer usablemedium including a program for transitioning between voice and datacommunications with a mobile vehicle. The program may include code tosend a switch-to-voice command signal from a call center modem pool tothe mobile vehicle. The program may include code to receive a vehicleswitch-to-voice acknowledgement signal at the call center. The programmay include code to switch a call from the call center modem pool to acall center advisor in response to the vehicle switch-to-voiceacknowledgement signal.

Another aspect of the present invention provides a system fortransitioning between voice and data communications with a mobilevehicle, including means for sending a switch-to-voice command signalfrom a call center modem pool to the mobile vehicle, means for receivinga vehicle switch-to-voice acknowledgement signal at the call center, andmeans for switching a call from the call center modem pool to a callcenter advisor in response to the vehicle switch-to-voiceacknowledgement signal.

The aforementioned, and other features and advantages of the inventionwill become further apparent from the following detailed description ofthe presently preferred embodiments, read in conjunction with theaccompanying drawings. The detailed description and drawings are merelyillustrative of the invention rather than limiting, the scope of theinvention being defined by the appended claims and equivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of one embodiment of a system fortransitioning between data and voice segments of a wirelesscommunication session with a mobile vehicle, in accordance with thecurrent invention;

FIG. 2 is a flow diagram of one embodiment of a method for transitioningbetween data and voice segments at the beginning of a wirelesscommunication session with a mobile vehicle, in accordance with thecurrent invention;

FIG. 3 is a flow diagram of another embodiment of a method fortransitioning between data and voice segments at the beginning of awireless communication session with a mobile vehicle, in accordance withthe current invention;

FIG. 4 is a flow diagram of one embodiment of a method for transitioningbetween data and voice segments in the middle of a wirelesscommunication session with a mobile vehicle; in accordance with thecurrent invention; and

FIG. 5 is a flow diagram of another embodiment of a method fortransitioning between data and voice segments in the middle of awireless communication session with a mobile vehicle, in accordance withthe current invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

One aspect of the present invention is to transition to and from a datacommunication segment and a voice segment within a single voice callestablished between a mobile vehicle and a telematics call center. Tonesand messages between wireless communication devices and call centers maybe used to signal information such as a device being ready to switchfrom a data mode to a voice mode or from a voice mode to a data mode. Amethod for transitioning between data and voice modes may use variouscombinations of signals, tones, bursts, messages and time sequences,which may include carrier signals, connect request or connect messages,vehicle identification (VID) messages, switch-to-voice (STV) signals andmessages, acknowledgement signals and messages, modem signaling, andtime delays.

FIG. 1 illustrates a call center architecture that does not requireevery advisor to have a dedicated modem or every modem to be associatedwith an advisor, but instead uses a bank or pool of digital modems and avoice/data switch for routing calls between the modem pool and theadvisors. This allows for more efficient scaling of call centeroperations. FIG. 2 and FIG. 3 present scenarios for transitions at thebeginning of a wireless communication session, and FIG. 4 and FIG. 5present scenarios for transitions during a communication session.

FIG. 1 shows an illustration of one embodiment of a system fortransitioning between data and voice segments within a wirelesscommunication session between a mobile vehicle and a call center, inaccordance with the present invention at 100. The system includessuitable hardware and software for sending a switch-to-voice commandsignal from a call center modem pool to the mobile vehicle, forreceiving a vehicle switch-to-voice acknowledgement signal at the callcenter, and for switching a call from the call center modem pool to acall center advisor.

Data and voice communication transition system 100 may include a mobilevehicle 110, a telematics unit 120, one or more wireless carrier systems140, one or more communication networks 150, one or more land networks160, and one or more call centers 170.

Mobile vehicle 110 may be a mobile vehicle equipped with suitablehardware and software for transmitting and receiving voice and datacommunications. Mobile vehicle 110 contains telematics unit 120 that mayinclude a vehicle communications processor. Telematics unit 120 mayinclude a digital signal processor (DSP), host processor or systemcontroller 122 connected to an analog, digital or dual-mode wirelessmodem 124, a global positioning system (GPS) unit 126, an in-vehiclememory 128, a microphone 130, one or more speakers 132, and anin-vehicle mobile phone 134. In-vehicle mobile phone 134 may be ananalog, digital, dual band, multi-band, dual-mode, or multi-modecellular phone. GPS unit 126 may provide, for example, longitude andlatitude coordinates of the vehicle.

System controller 122 may contain various computer programs that controlprogramming and operational modes of various systems within mobilevehicle 110. A voice-recognition application may be installed in systemcontroller 122 and translate human voice input through microphone 130 todigital signals. These signals may activate the programming mode andoperation modes, as well as input data. Output signals from systemcontroller 122 may be translated into digitized voice messages and maybe sent out through speaker 132.

System controller 122 may include a computer program for transitioningbetween voice and data communications with a telematics service callcenter. The computer program may include code to enter a voice-readymode or data-ready mode. System controller 122 may include a computerprogram to send requests or to respond to call center requests to switchto a voice mode or to switch to a data mode. A computer program maymonitor the calls originating from the mobile vehicle or those callsthat are received from the call center.

Mobile vehicle 110 via telematics unit 120 may send and receive radiotransmissions from wireless carrier system 140. Wireless carrier system140 may be any suitable system for transmitting a signal from mobilevehicle 110 to communication network 150.

Wireless carrier system 140 may be a wireless communications carrier.Wireless carrier system 140 may be, for example, a mobile telephonesystem. The mobile telephone system may be an analog mobile telephonesystem operating over a prescribed band nominally at 800 MHz. The mobiletelephone system may be a digital mobile telephone system operating overa prescribed band nominally at 800 MHz, 900 MHz, 1900 MHz, or anysuitable band capable of carrying mobile communications.

Communication network 150 may comprise services from one or more mobiletelephone switching offices and wireless networks. Communication network150 may be a wireless wide-area network (WAN). Communication network 150may connect wireless carrier system 140 to land network 160.Communication network 150 may be any suitable system or collection ofsystems for connecting wireless carrier system 140 to mobile vehicle 110and land network 160.

Mobile switching center (MSC) 152 may be one or more switches used forcall control and processing that serve as the interface betweencommunication network 150 and land network 160. MSC 152 may performsignaling functions necessary to establish calls to and from mobilestations.

Land network 160 may be a public-switched telephone network. Landnetwork 160 may be an Internet protocol (IP) network. Land network 160may be comprised of a wired network, an optical network, a fibernetwork, another wireless network, or any combination thereof. Landnetwork 160 may connect communication network 150 to call center 170.Communication network 150 and land network 160 may connect wirelesscarrier system 140 and mobile vehicle 110 to a communication node orcall center 170.

Call center 170 may be a telematics service call center. Call center 170may contain one or more voice and data switches 172, a modem pool 174with two or more analog, digital, or dual-mode modems, one or morecommunication services managers 176, one or more communication servicesdatabases 178, one or more bus systems 180 and one or more communicationservices advisors 190.

Call center 170 may be a location where many calls may be received andserviced at the same time, or where many calls may be sent at the sametime. The call center may be a telematics call center, prescribingcommunications to and from telematics unit 120 in mobile vehicle 110.The call center may be a voice call center, providing verbalcommunications between an advisor in the call center and a subscriber ina mobile vehicle. The call center may contain each of these functions.

Call center 170 may contain one or more voice and data switches 172.Voice and data switch 172 may be connected to land network 160. Voiceand data switch 172 may transmit voice or data transmissions from callcenter 170. Voice and data switch 172 also may receive voice or datatransmissions from telematics unit 120 in mobile vehicle 110 throughwireless carrier system 140 and communication network 150, MSC 152, andland network 160.

Voice and data switch 172 may receive from or send to one or morecommunication services managers 176 data transmissions via modem pool174. Communication services manager 176 may be any suitable hardware andsoftware capable of providing requested communication services totelematics unit 120 in mobile vehicle 110. Communication servicesmanager 176 may send to or receive from one or more communicationservices databases 178 data transmissions via bus system 180.

Voice and data switch 172 may receive or send voice communications to orfrom one more communication services advisor 190. Communication servicesadvisor 190 may be a real human in verbal communication with a user orsubscriber in mobile vehicle 110 via telematics unit 120.

Communication services advisor 190 may send or receive information to orfrom communication services manager 176 via bus system 180.Communication services advisor 190 may send or receive information to orfrom communication services database 178 via bus system 180.

Communication services manager 176 may provide one or more of a varietyof services, including enrollment services, navigation assistance,directory assistance, roadside assistance, business or residentialassistance, information services assistance, emergency assistance,communications assistance and activation services for replenishingpersonal call minutes. Communication services manager 176 may transmitdata to telematics unit 120 in mobile vehicle 110 through modem pool174, voice and data switch 172, land network 160, MSC 152, communicationnetwork 150, and wireless carrier system 140. Communication servicesmanager 176 may store or retrieve data and information fromcommunication services database 178. Communication services manager 176may provide requested information to communication services advisor 190.

Communication services advisor 190 may provide services to telematicsunit 120 in mobile vehicle 110. Services provided by communicationservices advisor 190 may include enrollment services, navigationassistance, directory assistance, roadside assistance, business orresidential assistance, information services assistance, emergencyassistance, and communications assistance. Information for theseservices may be retrieved by communication services advisor 190 fromcommunication services manager 176 and communication services database178. Communication services advisor 190 may communicate with telematicsunit 120 in mobile vehicle 110 through voice and data switch 172, landnetwork 160, MSC 152, communication network 150, and wireless carriersystem 140 using voice transmissions directly through voice and dataswitch 172, or using data transmissions directed through communicationservices manager 176, modem pool 174 and voice and data switch 172.

FIG. 2 shows a flow diagram of one embodiment of a method fortransitioning from data to voice wireless communications at thebeginning of a communication session with a mobile vehicle, inaccordance with the present invention at 200.

Data and voice communication transition method 200 may begin withtelematics unit (TU) 120 or call center (CC) 170 originating a voicecall, as seen at block 205. The call may be originated, for example,when the user of an in-vehicle phone desires to place a call to the callcenter so that services may be received. The call may be originated, forexample, when the call center needs to send information to thetelematics unit such as an update to a roaming list of a mobile phone orother configuration information. The telematics unit in the mobilevehicle call may monitor the call throughout a session to detect digitalmessages, modem carrier signals, or a switch-to-data command signal.

The first signals that are sent after the call is connected may includea switch-to-data command signal comprising, for example, a carriersignal or a modem carrier tone from the telematics service call center,as seen at block 210. The carrier signal may be, for example, at afrequency of nominally 2225 Hz. The switch-to-data command signal maycomprise at least one frequency tone, a sequence of tones, multipletones transmitted simultaneously, or a burst of tones. Theswitch-to-data command signal may be a switch-to-data request message,comprising one or more blocks of data. Generally, the transmission anddetection of a carrier signal from the call center may occur morequickly than the time to send a switch-to-data request message andtherefore, are more desirable.

The telematics unit may receive the switch-to-data command signal andswitch to a data-ready mode. During the data-ready mode, the telematicsunit may mute the audio to the mobile vehicle and monitor the signalsand messages coming from the call center. The telematics unit may send aswitch-to-data acknowledgement signal to the call center in response tothe switch-to-data command signal. The vehicle switch-to-dataacknowledgement signal may include, for example, at least one frequencytone such as a nominally 1270 Hz tone, or may be a tone sequence or aburst of tones. The vehicle switch-to-data acknowledgement signal may bea connect message. A connect message may be made from the telematicsunit to the call center, as seen at block 215.

The call center may respond to the connect message, as seen at block220. The call center may send, for example, a power request to thetelematics unit to set its modem carrier signal at a predeterminedvoltage or power level, or to adjust the power level incrementally. Whenthe response to the connect message or an alternative message is notreceived back at the telematics unit after a predetermined time, such asafter 300 milliseconds, the telematics unit may return to a voice-readymode. The telematics unit of the mobile vehicle may continue to monitorthe call for incoming messages and signals during the voice-ready modeor during a voice segment.

The telematics unit may send a vehicle identification (VID) messageafter receiving the calling center connect response, as seen at block225. The vehicle identification number may contain, for example, theserial number of the telematics unit, the vehicle identification number(VIN) assigned at a vehicle manufacturing plant, or an account numberassigned by a call center. The VID message may also contain GPS latitudeand longitude information.

The call center may send an acknowledgement (ACK) signal or message backto the telematics unit indicating that it received the VID message andthat the VID is authenticated, as seen at block 230. Other signals anddata messages may be exchanged between the calling center and thetelematics unit. The call center may send a switch-to-voice commandsignal from the call center modem pool to the mobile vehicle. Theswitch-to-voice command signal may include one or more frequency tones,a sequence of tones, or a tone burst. The switch-to-voice command signalmay include a switch-to-voice request message. The STV message mayindicate that the call center intends to move from a data segment to avoice segment with a human advisor in the call center.

The telematics unit may receive the switch-to-voice message and sendback a vehicle switch-to-voice acknowledgement signal or message to thecall center acknowledging that the STV request was received, as seen atblock 235. The vehicle switch-to-voice acknowledgement signal maycomprise a switch-to-voice acknowledgement message. The vehicleswitch-to-voice acknowledgement signal may comprise one or morefrequency tones, a sequence of tones, or a tone burst.

The telematics unit may begin a predetermined delay period that beginswhen the telematics unit sends back an acknowledgement to the STV signalor message. The delay period may be, for example, a period of 300milliseconds or a time less than two seconds. During this time, thetelematics unit may wait for an acknowledgement signal or message fromthe call center that indicates the vehicle switch-to-voiceacknowledgement signal or message from the telematics unit was received.

The call center may receive the switch-to-voice acknowledgement signalfrom the telematics unit, as seen at block 240. Then the call center maysend a call center switch-to-voice acknowledgement signal from the callcenter to the mobile vehicle in response to the vehicle switch-to-voiceacknowledgement signal. In other words, the call center may send back anacknowledgement that it received the STV acknowledgement of thetelematics unit. When the call center receives the vehicle STVacknowledgement signal, the call center may respond by switching thecall from the call center modem pool to a call center advisor. That is,the call center may switch to a voice mode, whereby a human advisor atthe call center can receive a voice transmission from the mobilevehicle.

The acknowledgement signal or message of the call center that was sentin response to the switch-to-voice acknowledgement of the telematicsunit may or may not be received by the telematics unit, as seen at block245.

The telematics unit of the mobile vehicle may enter a voice-ready modewhen a predetermined delay period has elapsed after the vehicleswitch-to-voice acknowledgement signal has been sent and noacknowledgement to the acknowledgement has been received. Thevoice-ready mode may include an un-muted audio signal. Alternatively,when the telematics unit receives a return acknowledgement signal fromthe call center, the telematics unit may enter a voice-ready mode,un-mute its audio and prepare for voice transmission, as seen at block250. In this case, the telematics unit may begin the voice segmentwithout waiting to the end of the delay period.

When the telematics unit does not receive the return acknowledgementsignal or message from the call center, it may wait to the end of thedelay period, as seen at block 255. Meanwhile, the telematics unit maydetect another STV signal or message, as seen at block 260. When anotherSTV is detected, the telematics unit may resend an STV acknowledgementsignal or message, remute the audio, and begin another delay period, asseen back at block 235. The sequence of acknowledgements may be repeatedagain from block 240 onward.

FIG. 3 shows a flow diagram of another embodiment of a method fortransitioning from data to voice wireless communications at thebeginning of a communication session with a mobile vehicle, inaccordance with the present invention at 300.

Data and voice communication transition method 300 may begin with atelematics unit or a telematics call center making a voice call, as seenat block 305. The call may originate from the vehicle, for example, whenthe user of an in-vehicle phone desires services from the call center.The call may originate from the call center, for example, when the callcenter needs to send information to the telematics unit such as anupdate to a roaming list of the mobile phone or other configurationinformation.

The data or first signals that are sent may include a switch-to-datacommand signal from the call center to the mobile vehicle. Theswitch-to-data command signal may be a switch-to-data message request, amodem carrier signal, a modem carrier tone, one or more frequency tones,a sequence of tones or a tone burst from the call center, as seen atblock 310. The signal may be a nominally 2225 Hz carrier tone, forexample. The telematics unit may send a connect message to the callcenter, as seen at block 315. Alternatively, the telematics unit maysend a vehicle switch-to-data acknowledgement signal comprising, forexample, at least one frequency tone such as a nominally 1270 Hz tone.Generally, the detection of a carrier signal from the call center mayoccur more quickly than the time required to receive a switch-to-datarequest signal or message.

The call center may respond to the connect message and may drop thecarrier signal, as seen at block 320. When the response to the connectmessage is not received back at the telematics unit after apredetermined time, such as after 300 milliseconds, the telematics unitmay send another connect message. The telematics unit and the callcenter may monitor the call continually for incoming signals.

The telematics unit may send a vehicle identification (VID) message, asseen at block 325. The vehicle identification message may include, forexample, the serial number of the telematics unit, the vehicleidentification number (VIN) assigned at a vehicle manufacturing plant,or an account number assigned by a call center. The VID message may alsocontain, for example, GPS latitude and longitude data.

The call center may send an acknowledgement signal or message (ACK) backto the telematics unit indicating that it received the VID message, andthen may send a switch-to-voice signal or message (STV), as seen atblock 330. The STV signal or message may indicate that the call centerintends to move from the data segment to a voice segment with a humanadvisor in the call center.

The call center may send a prescribed modem signal to direct thetelematics unit to switch to voice, as seen at block 335. The prescribedmodem signal may be, for example, a proprietary signal determined by thecall center or the manufacturer of the telematics unit. The prescribedmodem signal may be a carrier tone, a sequence of carrier tones, a setof carrier tones, a burst of carrier tones, or a tone or tone sequencewith various other signal modifications such as phase shifts.

The telematics unit may or may not receive the modem signal from thecall center, as seen at block 340. When the signal is not received, thetelematics unit may enter into a wait mode until an interval timerexpires or a modem signal is received from the call center, as seen atblock 360. When the signal is not received, the call center may continueto send a prescribed modem signal until a response or a connect messageis received successfully. When the interval timer expires, thetelematics unit may disconnect to end the connection with the callcenter, or wait a longer period of time if the interval timer isadjusted.

When the telematics unit receives the modem signal from the call center,it may send back a prescribed modem signal response, as seen at block345. The call center may or may not receive the modem signal from thetelematics unit, as seen at block 350.

When the call center does not receive the prescribed modem signalresponse, it may continue to send the switch-to-voice signal or messageor a modem signal until a response is received successfully, as seenback at block 330. When the call center receives the modem signal, itmay switch to a voice mode and route the call to an advisor, as seen atblock 355. The telematics unit also may switch to a voice-ready modeafter the predetermined delay time has lapsed or an acknowledgement tothe response has been received, and begin a voice segment with the callcenter.

FIG. 4 shows a flow diagram of one embodiment of a method fortransitioning from data to voice wireless communications during acommunication session with a mobile vehicle, in accordance with thepresent invention at 400. The voice communications may be previouslyestablished and in progress, as seen at block 405.

A switch-to-data command signal, i.e. a carrier signal, a modem carriertone, or a switch-to-data request message, may be sent from the callcenter to the telematics unit of the mobile vehicle, as seen at block410. The call may be monitored continuously at the mobile vehicle andthe switch-to-data command signal from the call center may be detectedat the mobile vehicle. The switch-to-data command signal may include oneor more frequency tones, a sequence of tones, or a burst of tones. Itmay include a nominally 2225 Hz tone.

The switch-to-data command signal may be received at the mobile vehicle,and the telematics unit may enter a data-ready mode that may includemuting the audio to the mobile vehicle. The telematics unit may send avehicle switch-to-data acknowledgement signal from the mobile vehicle tothe call center, comprising at least one frequency tone such as anominally 1270 Hz tone, or a connect message to the call center, as seenat block 415.

The vehicle switch-to-data acknowledgement signal may be received at thecall center. The call center may switch the call from the call centeradvisor to the call center modem pool. The call center may send aresponse to the connect message and optionally may send a systemmessage, as seen at block 420. The system message may include, forexample, a power request update or a global positioning system vehiclecoordinates request.

When the response to the connect message is not received back at thetelematics unit after a predetermined time, such as after 300milliseconds, the telematics unit may remain in data mode and sendanother connect message. The telematics unit and the call center maymonitor the call continually for incoming signals.

The telematics unit at the mobile vehicle may respond to the systemmessage, as seen at block 425. The response may include, for example, areply with data sent back to the call center. The response may include,for example, the telematics unit performing a requested operation andthen sending back data related to that operation. The call center andtelematics unit may proceed to exchange data, as seen at 430. This datamay include, for example, information from a variety of call centerservices, such as enrollment services, navigation assistance, directoryassistance, roadside assistance, business or residential assistance,information services assistance, emergency assistance, communicationsassistance and activation services for replenishing personal callminutes. The data also may include, for example, information on anoperation of the vehicle or telematics unit such as the updating of asystem identification table (SID) and a preferred roaming list of thetelematic unit, or the adusting of a vehicle parameter or comfortsetting of the mobile vehicle

The call center may send a switch-to-voice message after or, in a fewcases, during the data exchange, as seen at block 435. The telematicsunit may receive the STV message and send back an acknowledgement thatthe STV message was received, as seen at block 440. The telematics unitmay begin a predetermined delay period upon sending the STVacknowledgement.

The call center may or may not receive the acknowledgement to the STVmessage, as seen at block 445. When the acknowledgement message isreceived, the call center may switch to a voice mode, as seen at block450. The call may be switched and routed to a call center advisor.

When the acknowledgement is not received by the call center, the callcenter may resend a STV message and begin the acknowledgement processagain, as seen back at blocks 435, 440, and 445. If the telematics unitdoes not receive an acknowledgement from the call center to the vehicleswitch-to-voice acknowledgement before the delay period has ended, thetelematics unit may wait until the end of the delay period, at whichtime the telematics unit may be switched to a voice-ready mode, as seenat block 455.

After the call center and the telematics unit have switched to a voicemode, they may begin a voice segment, as seen at block 460.

FIG. 5 shows a flow diagram of another embodiment of a method fortransitioning from data to voice wireless communications during acommunication session with a mobile vehicle, in accordance with thepresent invention at 500.

Data and voice communication transition method 500 may begin with voicecommunications already established, as seen at block 505.

The call center may send a prescribed modem signal, as seen at block510. The telematics unit may receive the prescribed modem signal, andswitch out of voice mode into a data-ready mode by muting the audio tothe mobile vehicle. The telematics unit may reply by sending aprescribed modem signal and a connect message to the call center, asseen at block 515. The call center may continue to send the modem signaluntil a response from the vehicle is received successfully. The callthen may be switched from a call center advisor and routed to the modempool.

The call center may respond to the connect message and may send a systemmessage, as seen at block 520. When a response to the connect message isnot received back at the telematics unit after a predetermined time,such as after 300 milliseconds, the telematics unit may remain in voicemode and send another connect message. The telematics unit and the callcenter may monitor the call continually for incoming signals.

The telematics unit may respond to the system message, as seen at block525. The telematics unit and the call center then may exchange data in adata segment, as seen at block 530.

When operations or a subscriber request requires use of a call centeradvisor, the calling center may send a switch-to-voice message (STV)comprising a message or a prescribed modem signal, as seen at block 535.The STV message and modem signal may indicate that the call centerintends to move from the data segment to a voice segment with a humanadvisor in the call center. The telematics unit may send back aprescribed modem signal and begin a prescribed delay period, as seen atblock 540.

The call center may or may not receive the modem signal from thetelematics unit, as seen at block 545. When it does not receive thesignal, the call center may send another STV message and prescribedmodem signal, as seen back at block 535.

When the call center receives the prescribed modem switch-to-voiceacknowledgement signal, it may switch to a voice mode and route the callfrom the modem pool back to a call center advisor, as seen at block 550.After a delay period has ended or an acknowledgement to theacknowledgement has been received, the telematics unit also may switchto a voice-ready mode and begin a voice segment with the call center.

While the embodiments of the invention disclosed herein are presentlyconsidered to be preferred, various changes and modifications can bemade without departing from the spirit and scope of the invention. Thescope of the invention is indicated in the appended claims, and allchanges that come within the meaning and range of equivalents areintended to be embraced therein.

1. A method of transitioning between voice and data communications witha mobile vehicle, comprising: sending a switch-to-voice command signalfrom a call center modem pool to the mobile vehicle; receiving a vehicleswitch-to-voice acknowledgement signal at the call center; and switchinga call from the call center modem pool to a call center advisor inresponse to the vehicle switch-to-voice acknowledgement signal.
 2. Themethod of claim 1 wherein the switch-to-voice command signal comprises aswitch-to-voice request message.
 3. The method of claim 1 wherein theswitch-to-voice command signal comprises at least one frequency tone. 4.The method of claim 1 wherein the vehicle switch-to-voiceacknowledgement signal comprises a switch-to-voice acknowledgementmessage.
 5. The method of claim 1 wherein the vehicle switch-to-voiceacknowledgement signal comprises at least one frequency tone.
 6. Themethod of claim 1 further comprising: sending a call centerswitch-to-voice acknowledgement signal from the call center to themobile vehicle in response to the vehicle switch-to-voiceacknowledgement signal.
 7. The method of claim 6 further comprising:entering a voice-ready mode at the mobile vehicle in response to thecall center switch-to-voice acknowledgement signal.
 8. The method ofclaim 7 wherein the voice-ready mode comprises un-muting an audiosignal.
 9. (canceled)
 10. (canceled)
 11. The method of claim 1 furthercomprising: sending a switch-to-data command signal from the call centerto the mobile vehicle; receiving a vehicle switch-to-dataacknowledgement signal at the call center from the mobile vehicle; andswitching the call from the call center advisor to the call center modempool.
 12. The method of claim 11 wherein the switch-to-data commandsignal comprises at least one frequency tone.
 13. The method of claim 12wherein the switch-to-data command signal comprises a nominally 2225 Hztone.
 14. The method of claim 11 wherein the vehicle switch-to-dataacknowledgement signal comprises a nominally 1270 Hz tone.
 15. Themethod of claim 11 wherein the vehicle switch-to-data acknowledgementsignal comprises a connect message.
 16. The method of claim 1 furthercomprising: monitoring the call at the mobile vehicle; receiving aswitch-to-data command signal at the mobile vehicle from the callcenter; sending a vehicle switch-to-data acknowledgement signal from themobile vehicle to the call center; and switching to a data-ready mode atthe mobile vehicle.
 17. A computer usable medium including a program fortransitioning between voice and data communications with a mobilevehicle, comprising: computer program code to send a switch-to-voicecommand signal from a call center modem pool to the mobile vehicle;computer program code to receive a vehicle switch-to-voiceacknowledgement signal at the call center; and computer program code toswitch a call from the call center modem pool to a call center advisorin response to the vehicle switch-to-voice acknowledgement signal. 18.The computer usable medium of claim 17 further comprising: computerprogram code to send a call center switch-to-voice acknowledgementsignal from the call center to the mobile vehicle in response to thevehicle switch-to-voice acknowledgement signal.
 19. The computer usablemedium of claim 18 further comprising: computer program code to enter avoice-ready mode at the mobile vehicle in response to the call centerswitch-to-voice acknowledgement signal.
 20. (canceled)
 21. The computerusable medium of claim 17 further comprising: computer program code tosend a switch-to-data command signal from the call center to the mobilevehicle; computer program code to receive a vehicle switch-to-dataacknowledgement signal at the call center from the mobile vehicle; andcomputer program code to switch the call from the call center advisor tothe call center modem pool.
 22. The computer usable medium of claim 17further comprising: computer program code to monitor the call at themobile vehicle; computer program code to receive a switch-to-datacommand signal at the mobile vehicle from the call center; computerprogram code to send a vehicle switch-to-data acknowledgement signalfrom the mobile vehicle to the call center; and computer program code toswitch to a data-ready mode at the mobile vehicle.
 23. A system fortransitioning between voice and data communications with a mobilevehicle, comprising: means for sending a switch-to-voice command signalfrom a call center modem pool to the mobile vehicle; means for receivinga vehicle switch-to-voice acknowledgement signal at the call center; andmeans for switching a call from the call center modem pool to a callcenter advisor in response to the vehicle switch-to-voiceacknowledgement signal.
 24. The system of claim 23 further comprising:means for sending a call center switch-to-voice acknowledgement signalfrom the call center to the mobile vehicle in response to the vehicleswitch-to-voice acknowledgement signal.
 25. The system of claim 24further comprising: means for entering a voice-ready mode at the mobilevehicle in response to the call center switch-to-voice acknowledgementsignal.
 26. (canceled)
 27. The system of claim 23 further comprising:means for sending a switch-to-data command signal from the call centerto the mobile vehicle; means for receiving a vehicle switch-to-dataacknowledgement signal at the call center from the mobile vehicle; andmeans for switching the call from the call center advisor to the callcenter modem pool.
 28. The system of claim 23 further comprising: meansfor monitoring the call at the mobile vehicle; means for receiving aswitch-to-data command signal at the mobile vehicle from the callcenter; means for sending a vehicle switch-to-data acknowledgementsignal from the mobile vehicle to the call center; and means forswitching to a data-ready mode at the mobile vehicle.